Many internet users may be familiar with the panic that comes when a message appears on the screen saying a virus has infected your computer. Many internet users also do not realize that more often than not, those pop-ups are the beginnings of a popular scam.

In 2017, the federal Internet Crime Complaint Center (IC3) received 11,000 complaints related to tech support fraud. These scams come in all shapes and sizes, with con artists contacting people by phone, e-mail, pop-up messages and through search engines when people are trying to find legitimate computer help. The criminals often claim to be from well-known companies like Apple of Microsoft and say they detected malware on your computer. Inevitably, the communication ends with the scam artist asking you to pay for services you don’t need, or that may actually be harmful to your device.

But one scam technique that has appeared on Google’s Chrome internet browser may have users panicking that something dire has happened to their computer. These tech savvy scammers make your browser think it needs to save a file over and over, according to ArsTechnica. The browser can’t keep up and becomes unresponsive, but only after a phony error message tells the user to call a fake tech support number. And Chrome may not be the only internet browser affected. Malwarebytes security researcher Jérôme Segura tweeted that this screen-freezing scam also hit Firefox. ArsTechnica reports representatives from Google and Firefox say they are addressing the issue.

Remember nearly any legitimate tech support company will not contact you unsolicited, so you should never call these phone numbers.

There are other precautions to take to avoid becoming a victim, starting with the installation of ad-blocking software and making sure all software is up to date. If a so-called tech support company does contact you, be wary of any pressure to act quickly and never give remote access to your devices.

If a tech support scam does come your way, IC3 recommends shutting down the device immediately, ignoring any pop-ups telling you to do otherwise.

Whether or not you fall prey to a tech support scam, you should file a complaint with the IC3 and be as descriptive as possible, noting any phone numbers, names, websites and e-mail addresses used by the criminals. If you do get scammed, the Federal Trade Commission (FTC) says to get rid of any malware that you or the criminals may have installed. If you gave someone credit card information to order bogus services, let your credit card company know so they can reverse the charges.

The FTC also reports that following these scams that sell you unnecessary (and potentially harmful) services, you may get a call from someone asking if you were happy with the service. When you reply negatively, they offer a refund. They may even call to say the company is going out of business and offering refunds. Don’t fall for it. They will want your credit card or bank information, saying it’s necessary to deposit the refund. If you get a call like this, hang up on them and report it to the FTC.

Earlier this year, several defendants that used high-pressure techniques to peddle unneeded tech support settled with the FTC. A court order required Inbound Call Experts, LLC (doing business as Advanced Tech Support) to give legitimate refunds on average of $277 to 36,830 people. The more than $10 million settlement also blocks the defendants from misleading consumers into thinking they have security problems on their computers.